I have had the same problems with other types of mites. They are known as biting mites. I don't know if that's what you're dealing with, but there is a natural spray that I got that takes care of insects with a hard shell (the spray eats away at the shell so they die). I was lost without this spray. I literally had to quarantine different sections of my house for 3 days. The spray also handles lots of other mites, bedbugs, and ants. It is made of natural enzymes too. You can spray it on yourself, wash clothes in it, spray it in your house, and even bathe in it. I even used it while I was pregnant.0 It's not that expensive either. I bought the concentrate and got a spray bottle for like $25. It will probably last me 10-20 years. FYI, I don't work for this company or sell this product. You have to either call them or order it online. They shipped it to me quickly. Here's the link:
Kleen Green Enzymes is the product name
http://naturalginesis.com/products_kleengreen.html
Here's the link for the biting mite information. That could be what your daughter has.
http://www.naturalginesis.com/info_bitingmites.html
Even if it's not biting mites, the spray works on a lot of mites, bedbugs, insects, ants, etc.
Good luck!